Quite often, firearms use optical sighting devices, such as telescopic rifle scopes, for more accurate targeting. In order to align these sighting devices with the physical point of impact of the bullet at a given range, laser bore sighting devices are often used, such as disclosed in U.S. Pat. No. 5,432,598.
Laser bore sights currently use two methods of attachment to the firearm. The first method has a tapered arbor that centers the laser to the firearm bore via the muzzle bore, as in U.S. Pat. No. 5,432,598. A second method allows the laser bore sighter to take the shape of a bullet casing and to be inserted into the breach of the firearm, as in U.S. Pat. No. 5,787,631.
Both methods require separate pieces for each caliber of firearm being tested. In the first method, the arbor must be sized to fit the particular caliber being tested. In the second method, the shape of the sighter must conform to the shape of the chamber in the receiver in which it is used. Thus, both methods require multiple pieces, assemblies or units to test the various caliber firearms commonly used today. Even so called universal bore sights are not useable on all calibers without multiple attachments.
A need exists to reduce the cost and complexity of these optical sighting alignment devices.